Environmental guidelines often require effective belt cleaning apparatus. Even apart from the need to meet these environmental requirements, maintaining a clean plant has many operational, maintenance and health advantages.
When coal is moved on a conveyor belt, a layer of surface embedded particulate material often will build up on the belt surface. Such material includes particles of coal and coal dust, and may be in discrete particle form or the particles may be packed tightly together. Coal dust will get trapped in the irregular surfaces of the belt. Belts used in the transport of coal and like bulk material are usually made of reinforced rubber or rubber-like material which has cracks and dust gets into and lodges in these cracks.
The apparatus of the present invention is designed to remove both surface embedded particulate material from a transport belt for coal and the like, and also to remove dust from the belt cracks. These materials, particularly dust in the belt cracks, unless removed, will eventually become airborne due to the bouncing movement of the belt and its flexing as it passes over rollers and around pulleys. Belt cleaning apparatus has in the past been designed to remove carry back, but we are not aware of any completely successful attempt at removing the particulate material that accumulates in the cracks.
In accordance with the embodiment of the invention about to be described, water and a scraper blade combine to remove embedded particulate material including dust from the belt surface and from the cracks in the belt. The scraper blade is supported with its scraping edge extending across the width of the belt in contact with the material-supporting surface of the belt as it advances. A spray of liquid, which may be ordinary water, is directed into the surface cracks adjacent to the point of contact with the scraper blade. The blade and liquid discharge cooperate in removing particulate material including dust from the cracks. The liquid penetrates the belt subsurface and the blade not only scrapes the surface of the belt but acts to squeeze the water or liquid and embedded particulate material from the belt.
Further in accordance with the specific embodiment to be described, the liquid is directed against a surface of the scraper blade, and is deflected into the cracks in the surface of the belt. The blade thus not only cooperates in the cleaning action, but the force of the liquid against the blade prevents build up and keeps the blade relatively clean at all times.
A second stream of liquid is sprayed against the belt surface upstream of the point of contact with the scraper blade, serving to remove much of the surface particulate material before reaching the point of the joint scraper/liquid action.
Preferably, a second identical washer/scraper arrangement is installed beyond the first washer/scraper arrangement.
Beyond the scraper blade, a roller may be provided to squeeze water and any residual dust out of the belt.
A V-plow shaped scraper is provided on the side of the belt opposite the load-supporting surface. Ahead of the V-plow, a liquid stream cleans the surface of the belt. The V-plow removes the liquid and accumulated material from the belt surface. This plow also serves as a backing member for the scrapers mounted below the belt, and insures that the belt is flat so that the entire belt width is scraped on both surfaces.
A drainage receptacle is preferably placed beneath the belt enclosing the washer/scraper units. This receptacle has a sloping bottom which is washed down by a continuous liquid stream, to facilitate the removal of the water and particulate material.
One objective of this invention is to provide apparatus for cleaning a transport belt for bulk materials such as coal which has some or all of the features referred to above. This apparatus greatly reduces the cost associated with maintaining a safe and healthful working environment as well as the cost of equipment repair and replacement.
Other objectives are to provide an apparatus for cleaning a coal belt or the like which is rugged and durable in operation, composed of a relatively few simple parts, and relatively easy to install and maintain.
Other objectives, features and advantages of the invention will become more apparent as the following description proceeds, especially when taken with the accompanying drawings.